GloFo is booked solid through to 2023[0], and that’s without AMD’s volume. Again, not everything needs to be on leading edge nodes. Since when are trailing edge processes not viable? I have no idea where you’re getting that idea from. For example, in Q1 2021 TSMC made more than 50% of its revenue in processes older than 7nm.[1] Just so you know, TSMC intends to keep ramping up >7nm production for a few more years. There is so much demand for all kinds of nodes that it’s hilarious that you’re still trying to make this argument.
We're talking about processors here, not random semiconductors that have no market incentives to move to newer process nodes.
Let's say you've got a team of engineers ready to design the next generation of their 64-bit RISC-V core. You've just completed your 12nm design, and are trying to target where the market will be in 24-48 months when your new design is finished. Are you going to:
a) design a new core targeting the same 12nm node your previous design was built on
b) target a newer 7nm node that gives you:
1) lower power from the node shrink
2) higher clock speeds thanks to the node shrink
3) higher performance thanks to increased execution resources made possible because of the node shrink
4) lower cost thanks to smaller die sizes made possible by the node shrink
Most teams of electrical engineers will select option (b).
I am not saying there is no value in older semiconductor fabs. I am saying that for CPUs, there is serious market pressure is to move on to more advanced nodes, and that for a company like GloFo it is becoming less competitive and falling behind in the market for CPUs. Personally, I consider this a bad thing for a fab that came into being in part because it was once a performance leader with high end AMD CPUs. Sure they can change what market they're targeting - that's just survival - but it's generally a bad thing to lose what was once one's greatest strength.
0: https://www.cnbc.com/2021/10/30/globalfoundries-ceo-were-sol...
1: https://www.anandtech.com/show/16621/tsmc-q1-2021-process-no...